Jet propulsion boat

ABSTRACT

This invention of the Jet Propulsion boat, shallow-draft hull molded with plastic, is a inboard boat operated by means of propeller that is firmly installed on the propeller stand perpendicularly protruded from the hull with its axle shaft supported by the Seal Bearing Box whereby to link with the shaft of the drive power unit, selectively among the mechanism such as pedal powered mechanism, D.C. motor or Gas engine; which is to be detachably set up to the Drive Power Unit Housing Device that is installed at the central bottom of the hull; whereat the drive power unit can be activated to operate the propeller while creating pressure inside the Pressure Chamber with the water from the inlet opening and then forcing out the water through the constricted exhaust opening with powerful thrusts causing reaction to propel the boat.

BACKGROUND OF THE INVENTION

[0001] This invention as the jet propulsion boating elements is very much related with my first U.S. Pat. No. 4341058 “Exercycle Mower Apparatus ” granted on Jul. 27, 1982 and the Second and third U.S. Pat. No. 4657514 “Amphibious Pedal Powered Sailboat” on Apr. 14, 1987.

[0002] That is, in 1982 while developing the gearing system of the Exercycle Mower, it was found the fact that the minimum revolutions of the grass cutting blade required 900 r.p.m. whereas subsequently the gearing mechanism was settled with the design of 1,040 r.p.m. which is equivalent to the small capacity of a outboard Gas engine; and that during the period of developing the invention “Amphibious Pedal Powered Sail Boat”, it was found that the stem of the boat hull molded with fiberglass reinforced resin is comprised with the perpendicularly projected screw propeller stand firmly holding with a seal bearing box and upper half round cavity covering screw propeller whereby the round cavity behind the screw propeller significantly affected to enhance efficiency of its thrusting power, while reducing propeller noise as compared with a outboard motor boat. As such that, the present invention of the jet propulsion inboard boat is merited with the intensive research achievements during the development of the previously U.S. patented inventions including the “Pedal Powered Exercycle Mower” and the “Pedal Powered Sailboat.

[0003] The present invention of inboard boat is provided with the Pressure Chamber in the stern of the hull, and the screw propeller is installed in the forward section of the Pressure Chamber with the propeller shaft that is supported by the Seal Bearing Box firmly fixed at the lower part of the screw propeller stand protruded from the central part of the boat hull whereby to connect the screw propeller shaft with the shaft of the Drive Power Unit. As such that, this invention of the inboard boat is remarkably distinguished from other inboard boat in the following facts: 1) the boat hull has a hollow cavity running from the central part of the hull to the end of the stem, 2) the Pressure Chamber is comprised of the upper part and lower part, and the upper part is processed together with the boat hull and the lower part separately processed is joined with the upper part by bolts and nuts, and 3) the screw propeller is placed at the point right inside of the inlet opening of the Pressure Chamber, whereby the propeller is well protected from possible damage by rocks or other things in the water.

[0004] In this context, numerous research was carried out through the web side in domestic and world wide, however, there were no significant answers to the query—only saying that there is a remarkable improvement in the field of airplane jet propulsion, but no significant development in jet propulsion boating. Although the applicant of the present invention searched through the internet of www.uspto.gov/ with use of paraphrases such as “Jet Propulsion Pedal Boat” and “Jet Propulsion Motor Boat” that were responded with “No patents have matched with your query.” 

I claim:
 1. Jet Propulsion Boat, as a light weight inboard boat, has a Pressure Chamber that is comprised of the upper part and the lower part; the upper part is combined with the boat hull, and the lower part is detachably joined with the upper part by means of bolts and nuts;
 2. The Jet Propulsion Boat as mentioned in Article 1 above has a Screw Propeller Stand which is perpendicularly protruded downward thus to firmly holding the Screw Propeller by means of Propeller Shaft that is supported by the Seal Bearing Box having grooved end to connect with the female grooved end of the Drive Power Unit shaft;
 3. The Drive Power Unit Housing Device of the Jet Propulsion Boat is permanently installed at the center of the longitudinally elevated boat hull, having the Steering Wheel thereon to manipulate the Rudder at the stern end by means of bevel gears and transmission shaft, and having the Drive Power Unit Holding Bolt in front of the Steering Wheel base whereby to hold the Drive Power Unit, selectively one of three power sources such as the pedal powered mechanism, D.C. Motor and Gas engine; the female grooved end of the Axle Shaft of the drive power unit is to connect with the grooved male shaft end of the Screw Propeller;
 4. The Pressure Chamber as mentioned in Article 1 above is shaped with cylindrical channel consisting of the inlet opening in front of the Screw Propeller and the Exhaust Opening which is markedly constricted to function for Jet Propulsion when the Screw Propeller is in activation. 